Anthony D. Weiner, the long exiled, ostracized, and written-off former congressman, re-emerged on the city’s political stage Thursday as his essential, unadulterated self, at once gratingly self-mythologizing and charmingly self-effacing.

He told a young woman in Harlem that she should remember Thursday as the day she had met him on her way to the White House. His suggested recollection: “Little bit skinny, big nose, but I liked him. And he inspired me.”

He exhausted a subway heckler named Lorie who sought but failed to outsmart him, hurling question after question about education and homelessness, which he deftly parried.

“What else?” he asked her.

She brought up his raunchy tweets.

“And we were doing so well,” Weiner told her, in mock disappointment.

Her advice to him: Stay off Facebook and Twitter. “Ask for forgiveness,” she told him.

Even in a city that relishes its over-the-top political spectacles, here was a singularly circuslike quality to Weiner’s first day on the campaign trail.

He began at 125th Street and Lenox Avenue in Harlem, dipped underground onto the subway, then returned to the streets of lower Manhattan, trailed at all times by a few dozen reporters and a handful of police officers called in to keep the peace.

Weiner seemed determined to withstand every last inquiry, in a form of public catharsis, just as he did the afternoon he acknowledged his misdeeds nearly two years ago to the day in 2011. Why exactly was he running now?

“It was a process of figuring out what felt right for the city, what felt right for me,” he told reporters. “I apologize if I inconvenienced you with the scheduling.”

Who would run his campaign’s social media operations?

“What’s that?” he asked mischievously.

Would he reveal the contents of the texts he sent to women?

“The New York Post already asked me that yesterday,” he retorted.

By 9 a.m., he reached his next destination, WNYC-FM, where he planned to sit for a live interview. He bid the media goodbye, in a strangely formal way, all but thanking for them tagging along for the show.